Chill



C. G. RAIBLE June 19, 1956 CHILL INVENTOR. CHARLES GREIF RAIBLE ATTY.

iinited States Patent 6 CHILL Charles Greif Raible, Chesterland, Ohio,assignor to Fanner Manufacturing Company, Cleveland, Ohio, a corporationof Ohio Application August 5, 1953, Serial No. 372,509

6 Claims. (Cl. 22-174) This invention relates to improvements in chillsfor use in producing metal castings from molten metal poured into amold.

In producing metal castings in this manner, it is essential to providemeans for maintaining the cooling rate uniform in the various portionsof the casting in order to avoid resulting defects. These defects occuras the result of the fact that the center portion of heavy metalsections cools more slowly than the outer portions. As the hot metalcools, it shrinks, and the outer portions of the metal solidify first soas to fix the volume of the casting. During cooling, the metal tends tomaintain uniform density of structure. Thus, as continued contractionprogresses toward the center of the mass, eventually there is not enoughmetal to fill the outer volume with uniform density of structure.

In order to overcome such a problem, there have been proposed variousforms of internal chills formed of masses of cold metals and sopositioned in the molds so as to be fused in the molten metals, while atail portion extends into the mold to facilitate the transfer of heataway from the internal structure of the casting, their purpose being toassist in making uniform the rate of cooling.

It is therefore one of the primary objects of my invention to provide animproved chill which, for a given amount of mass of metal, is sodesigned as to have the maximum surface area for contact with the moltenmetal of the casting in order to more efficiently act as a heat transferagent from the interior of the molten metal casting through its outersurface into the mold.

With the foregoing and other objects in view, the invention resides inthe combination of parts and in the details of construction hereinafterset forth in the following specification and appended claims, certainembodiments therefore being illustrated in the accompanying drawings, inwhich:

Figure 1 is a view in vertical section taken through a mold, showing themolten metal at a higher level and also showing a lower verticallydisposed chill and a midlevel horizontally disposed chill, bothsubmerged in molten metal, and an upper vertically disposed chillpartially submerged in molten metal;

Figure 2 is an enlarged detail view in perspective of my improved chill;

Figure 3 is a view in front elevation of the nose portion of the chill;

Figure 4 is a view in section taken along line 44 of Figure 3; and

Figure 5 is a view in section taken along line 55 of Figure 4.

Referring moreparticularly tothe drawings, Figure 1 schematically showsthe environment in which my chill may be used, the showing including anouter frame work 1, filled with a mold of suitable material 2, such assand, the mold being provided with a cavity 3 of desired size andcontour to receive molten metal 4 which is poured through the opening 5to assume the overall shape and size determined by the cavity 3 in themold. For mere purposes of illustration, I have shown a lower chill withthe body portion 6 extending into the cavity to be surrounded by andfused with a molten metal of the casting 4, and a tail portion 7extending into the mold 2. The same is true of the horizontally disposedchill with its body portion 8 and tail portion 9 and with the upperchill with its body portion 10 and its tail portion 11.

In Figures 2, 3, 4 and 5, I have illustrated my preferred form of chillin greater detail. Here, I have shown the chill to include a tailportion 12 that tapers in thickness to a point 13 at its rear end. Themain body portion of the chill, forward of the tail portion 12, ispreferably formed to be star-shaped, as shown in Figures 2, 3 and 5. Inother words, instead of having the main body portion of the chill to beof a solid mass of rectangular or cylindrical form, or the like, Iprefer to have it formed of four fins, or vanes, 14, 15, 16 and 17,whose radial planes intersect and whose radial length is far greaterthan the center mass, formed by the joining of the radial fins, in orderto obtain the maximum surface area for the amount of metal employedthroughout the length of the major portion of the chill. In addition,each of these vanes is preferably formed to taper to gradually decreasein thickness toward their radial outer extremities. In addition, Iprefer to have the forward edges each inclined forwardly to merge into aconical nose 18. I have illustrated this in Figure 2 by designating suchforward sloping edges 19, 20 and 21 of vanes 14, 17 and 16. Similarly,the rear portion of the vanes are inclined radially rearwardly inwardlyat an angle to merge into the tail portion 12, Figure 4 showing suchrearward inclined edges of vane 17 at 22 and vane 15 at 23.

Thus, with a chill of this design, as the molten metal is poured intothe mold, and as its liquid level rises gradually within the mold, thelowermost chill, or chills, will be gradually enveloped, so that at notime will an entire surface be completely enveloped instantaneously.This is because the nature of the design of the chill is such that,regardless of its disposition within the mold, there is presented no topsurface of any of the chills that will be horizontal. Thus, no gaseswill be trapped along any portion of the chill, but will escape alongthe inclined surfaces until the uppermost point of the upper chill hasbeen reached by the liquid level of the molten metal.

I am aware of the fact that certain internal chills have been providedin which the main body portion is made of bar stock of square, conical,or cylindrical, cross-section. Such a chill has been found to beeffective for chilling around a given restricted area. However, I havefound, by actual practice, that the chilling of a steel casting, or thechilling of any other type of metal, is strictly a matter of heattransfer. By analogy, it is a phenomenon similar to the heat transfer ofan ordinary radiator, whether of cast iron, copper, or the like, inwhich it is the surface area that is of importance in heat transfer. Thesame is true of chilling at any given point in a metallic casting. Thegreater surface area of an internal chill that can be brought intocontact with the molten metal in the mold, the more readily efficientchilling of the casting may be accomplished Without the addition of alarge volume of a point where it merges with the main body portion. Themain body portion, as distinguished from being of square or circularcross-sectional area, is in reality of a size comparable to thecross-section area of the forward end of the tail portion, because it isjust large enough to form a juncture point for the intersecting fins, orvanes. In attempting to clearly describe this cross-sectionalconfiguration, I have referred to it as being starshaped without anyinference as to limitation as to the number of vanes, or fins, that Imay desire to employ. My main point is to not merely add radiating fins,or vanes, to a square or cylindrical piece of bar stock, but on thecontrary, to form the body portion of the chill as nearly completely ofthe vanes, or fins, as structurally expedient, with its transversecross-sectional area 24 being as small as possible, the length of eachvane being appreciably greater than the transverse cross-sectionaldimension of the main body portion, as shown in Figures 2, 3 and 5increased heat transferring radiating surface area and the reduction ofthe localized center mass represented at 24 to the minimum.

I claim:

1. In combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion of relatively small transversecross section positioned to extend into the mold and a main body portionpositioned to extend into the cavity to be surrounded by said moltenmetal and embedded therein for effecting the transfer of heat from saidmolten metal outwardly into said mold for the purpose of chilling themetal casting resulting from said molten metal, said chill being formedof metal in which said tail and body are integral, said body portionincluding a plurality of longitudinal radially extending vanes whoseradial planes intersect, the radial length of each vane beingappreciably greater than the transverse cross-sectional dimension ofsaid body portion.

2. In combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion positioned to extend into the moldand a main body portion positioned to extend into the cavity to besurrounded by said molten metal and embedded therein for effecting thetransfer of heat from said molten metal outwardly into said mold for thepurpose of chilling the metal casting resulting from said molten metal,said chill being formed of metal in which said tail and body areintegral, said tail being tapered from its forward portion where itmerges with said body portion to decrease in thickness toward its rearend, said body portion being of appreciable length and being of suchtransverse cross-section as to include a plurality of longitudinalradially extending vanes whose radial planes intersect, the radiallength of each vane being appreciably greater than the transversecrossscctional dimension of said body portion.

3. In combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion positioned to extend into the moldand a main body portion positioned to extend into the cavity to besurrounded by said molten metal and embedded therein for effecting thetransfer of heat from said molten metal outwardly into said mold for thepurpose of chilling the metal casting resulting from said molten metal,said chill being formed of metal in which said tail and body areintegral, said tail being tapered from its forward portion where itmerges with said body portion to decrease in thickness toward its rearend, said body portion being of appreciable length and being of suchtransverse cross-section as to include a plurality of longitudinalradially extending vanes whose radial planes intersect, the radiallength of each vane being appreciably greater than the cross-sectionaldimension of said body portion, each of said vanes being tapered todecrease in wall thickness radially outwardly.

4. In combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion positioned to extend into the moldand a main body portion positioned to extend into the cavity to beSurrounded by said molten metal and embedded therein for effecting thetransfer of heat from said molten metal outwardly into said mold for thepurpose of chilling the metal casting resulting from said molten metal,said chill being formed of metal in which said tail and body areintegral, said tail being tapered from it forward portion where itmerges with said body portion to decrease in thickness toward its rearend, said body portion being of appreciable length and being of suchtransverse crosssection as to include a plurality of longitudinalradially extending vanes whose radial planes intersect, the radiallength of each vane being appreciably greater than the cross-sectionaldimension of said body portion, each of said vanes being tapered todecrease in wall thickness radially outwardly, the edges of forwardportions of said vanes being inclined forwardly to converge centrallyinto a conical forward nose.

5. in combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion positioned to extend into the moldand a main body portion positioned to extend into the cavity to besurrounded by said molten metal and embedded therein for effecting thetransfer of heat from said molten metal outwardly into said mold for thepurpose of chilling the metal casting resulting from said molten metal,said chill being formed of metal in which said tail and body areintegral, said tail being tapered from its forward portion where itmerges with said body portion to decrease in thickness toward its rearend, said body portion being of appreciable length and being of suchtransverse crosssection as to include a plurality of longitudinalradially extending vanes whose radial planes intersect, the radiallength of each vane being appreciably greater than the cross-sectionaldimension of said body portion, each of said vanes being tapered todecrease in wall thickness radially outwardly, the edges of forwardportions of said vanes being inclined forwardly to converge centrallyinto a conical forward nose and the edges of rear portions of said vanesbeing inclined rearwardly to converge centrally to merge with theforward end of said tail portion.

6. In combination with a mold having a cavity for receiving moltenmetal, a chill having a tail portion positioned to extend into the moldand a main body portion positioned to extend into the cavity to besurrounded by said molten metal and embedded therein for effecting thetransfer of heat from said molten metal outwardly into said mold for thepurpose of chilling the metal casting resulting from said molten metal,said chill being formed of metal in which said tail and body areintegral, said tail being tapered from its forward portion where itmerges with said body portion to decrease in thickness toward its rearend, said body portion being of appreciable length and being of suchtransverse cross-section as to include a plurality of longitudinalradially extending vanes whose radial planes intersect to form a centralportion of transverse cross-sectional areas substantially equal to thatof the transverse cross-sectional area of the forward portion of saidtail, the radial length of each vane being appreciably greater than thetransverse cross-sectional dimension of said body portion, each of saidvanes being tapered to decrease in wall thickness radially outwardly,the edges of forward portions of said vanes being inclined forwardly toconverge centrally into a conical forward nose and the edges of rearportions of said vanes being inclined rearwardly to converge centrallyto merge with the forward end of said tail portion.

References Cited in the file of this patent UNITED STATES PATENTS

